Admin panel won't load completely.

I am evaluating ISPConfig on a test server and not having much success. I am using Fedora 4 on a Dual Pentium III server. I followed the "perfect" installation instructions and had no errors during install. However, when I try to access the control panel on port 81 it never loads completely. Sometimes the top nav bar will not display, other times it's the right or left frame that will be blank. It's random. This happens on IE and Firefox. I have tried both https and http and tried many different entries in the config.php for the URL. The server is behind a DSL router at IP address 192.168.0.10 using NAT passing all ports. Port 80 data (or any other service) doesn't seem to have problems, just the ISPConfig panel at 81.